(-2a^3 bc)^3 =(-2a^3)^3*b^3*c^3=-8^9b^3c^3
-8a^6b^3c^3
=(-2)^3*(a^3)^3*b^3*c^3=-8a^9b^3c^3
(-2a^3 bc)^3 =-8×a^(3×3)×b^(1×3)× c^(1×3 )=-8a^9b^3c^3